The parent application teaches a water filtration apparatus which is particularly suited for domestic use to improve the potability of water. The present invention relates to countertop water filter units having changeable filter media. Filter units with changeable media allow for the removal of a used filter cartridge and the insertion of a clean filter cartridge, thereby extending the usable life of the water filter unit with the scale of economy for the end user.
It is a well-known fact that, as population densities increase, it becomes more and more difficult to provide sufficient water of satisfactory purity and potability for domestic use. The purity and quality of drinking water, even from municipal water systems, is increasingly poor and very often unsatisfactory. Furthermore, in addition to industrial and domestic pollution related to high population densities, drinking water in many locations has both a disagreeable odor and aftertaste because of dissolved materials in the water, which, while not necessarily harmful, reduce the potability of the water.
Contaminants which affect the taste of the water are particularly annoying to people who are not residents of the area from where the water is supplied. Additionally, contaminants which affect the taste of the water are particularly annoying when water is used for particular purposes, such as brewing coffee or tea, where the taste of the end product is significantly effected by the contamination.
Because of these factors, a number of filtration devices have been proposed in the past for improving drinking water. However, these prior art devices have been generally ineffective because of deficiencies and inadequacies of design. Most commonly, such filters have employed only one filtration medium, generally charcoal, and have been limited in effectiveness to remove only those contaminants for which that medium is effective. These contaminants are generally organic materials and odoriferous materials, such as dissolved halogens, which may combine readily with the carbon and the charcoal. However, there are many serious contaminants, such as disease- and illness-causing bacteria, which are not generally removed by charcoal. It has been generally thought that it is necessary, in order to remove bacteria, to boil or distill drinking water for domestic use.
Additionally, many of the domestic water filtration apparatuses are of the countertop type. These generally consist of vertical cylinders which receive water from a diverter valve attached to a sink faucet and introduce unpurified water to the bottom of a charcoal stack, flow the water upward against gravity and dispense the filtered water from a spigot located at the top of the charcoal stack. The configuration of these units is bulky and requires that the units be placed adjacent to the sink where they interfere with household tasks of washing dishes, etc. Moreover, the tubing interconnecting the diverter valve and the filtration apparatus is obtrusive and possibly dangerous to those people working near the sink. In addition, many filters are single charge units and do not provide for changing the filter medium after its filtering ability is exhausted. Thus the entire apparatus must be changed periodically, increasing the cost of the water filter.
Accordingly, there has been a continuing need for a water filter system which may be readily adapted for use as a domestic appliance for connection to domestic water supplies, which are often considered to be suitable for use for potable water, but which may be dangerously toxic. In this regard, therefore, there has been a long felt need for a water purification system which is easily utilized in conjunction with a household water distribution system, which may be used only when it is necessary to provide a supply of drinking or cooking water, is unobtrusive and may otherwise be easily stored out of the way, and is inexpensive due to the changeability of a changeable filter cartridge system. The present invention provides a unique water purification system which is particularly well adapted for use as a domestic appliance, which holds several advantages and superior features, which will be appreciated by those skilled in the art upon reading the following description of the invention with reference to its preferred embodiments.